Technology describing epithelial circulating cancer cells (CCC) was first established in Cell Works' Phase I study. This study was based on prostate cancer and has been expanded to include breast, colon, gastric, liver and pancreatic cancer with the same universal test protocol for all six epithelial cancers. Laboratory validation demonstrated the reliability and reproducibility of the tests by spiking cultured cancer cells into normal blood samples with a recovery rate typically in the range of 60-80%. The goal of this clinical study is to demonstrate the clinical utility of the CCCT (BloodBiopsySM) for the management of metastatic colon and breast cancer. These clinical studies will be done in collaboration with University of Maryland, VA Medical Center and Roswell Park Cancer Center. The primary aim will be to determine the numbers of cells and percent of patients positive prior to treatment and at intervals coincident with treatment and tumor assessment in known lymph node-positive or metastatic breast and colon cancer patients. Within the limitations of funds and time to be provided by this NCI grant, we intend to determine, to the extent possible, any trend or correlation between biomarkers and patient outcome. In addition, we intend to determine to the extent possible any trend or correlation between circulating cells and patient outcome. Specifically, is there a relationship between cell numbers before and after treatment and patient outcome? Is there a relationship between the clinical data (location of metastasis, degree of tumor burden, previous drug treatment and progression of disease) and CCCT results, both negative and positive? A total of about 1500 tests for 500 patients will be done within this 3-year study for these two cancers. This is the first clinical study searching for a trend or correlation between circulating cancer cells and the clinical data from patients with metastatic cancer. It is also the first study to assess whether specific biomarkers expressed on isolated cells can be used as therapeutic indicators to select patients who are most apt to benefit from new specific anticancer drugs. We anticipate that the outcome of this study will demonstrate the utility of the CCCT to serve as a therapeutic indicator for future clinical trials of new anticancer drugs.